The invention relates to an internal combustion engine gas exchange valve actuator and is used to displace one or more internal combustion engine valves thereby improving the operation and extending the capabilities of the engine. The actuator includes a casing (2) attached to the engine head (1) and with a hollow cylinder (3) formed inside it and containing a reciprocating piston (6) with a piston rod. Provision is made in the casing (2) which is closed by a cap (4), for a loop for controlled charging and discharging of the pressurized fluid and for a solenoid valve with direct electromagnetic control. The solenoid valve is positioned above the piston (6) and is formed as a plunger (19) having a lower cylindrical widening with axial orifices (20) and an upper part with a central recess (22) and radial orifices (23) and (24).

A compression-release engine brake system operating an exhaust valve of an engine during a compression-release engine braking operation. The compression-release brake system comprises an exhaust rocker arm and a brake reset device disposed in a reset bore formed in the exhaust rocker arm. The brake reset device comprises a reset check valve, a slider-piston slidably disposed in the reset bore and an external slider bias spring biasing the piston foot away from the brake reset device. The external slider bias spring is disposed outside the reset bore and around the piston-slider. The brake reset device permits pressurized hydraulic fluid to flow from a supply conduit to a reset conduit to supply a brake actuation piston when the reset check valve is open. The actuation piston extends and engages the exhaust valve toward the end of a compression stroke of the internal combustion engine, and the brake reset device resets.

A compression-release engine brake system operating an exhaust valve of an engine during a compression-release engine braking operation. The compression-release brake system comprises an exhaust rocker arm and a brake reset device disposed in a reset bore formed in the exhaust rocker arm. The brake reset device comprises a reset check valve, a slider-piston slidably disposed in the reset bore and an external slider bias spring biasing the piston foot away from the brake reset device. The external slider bias spring is disposed outside the reset bore and around the piston-slider. The brake reset device permits pressurized hydraulic fluid to flow from a supply conduit to a reset conduit to supply a brake actuation piston when the reset check valve is open. The actuation piston extends and engages the exhaust valve toward the end of a compression stroke of the internal combustion engine, and the brake reset device resets.

A valve actuation system comprises a valve actuation motion source configured to provide main and auxiliary valve actuation motions for actuating at least one engine valve via a valve actuation load path. A lost motion subtracting mechanism is arranged in a valve bridge and configured, in a first default operating state, to convey at least the main valve actuation motion and configured, in a first activated state, to lose the main valve actuation motion and the auxiliary valve actuation motion. Additionally, a lost motion adding mechanism is arranged in a rocker arm and configured, in a second default operating state, to lose the auxiliary valve actuation motion and configured, in a second activated state, to convey the auxiliary valve actuation motion, wherein the lost motion adding mechanism is parallel with the lost motion subtracting mechanism in the valve actuation load path at least during the second activated state.

A valve actuation system comprises a valve actuation motion source configured to provide main and auxiliary valve actuation motions for actuating at least one engine valve via a valve actuation load path. A lost motion subtracting mechanism is arranged in a valve bridge and configured, in a first default operating state, to convey at least the main valve actuation motion and configured, in a first activated state, to lose the main valve actuation motion and the auxiliary valve actuation motion. Additionally, a lost motion adding mechanism is arranged in a rocker arm and configured, in a second default operating state, to lose the auxiliary valve actuation motion and configured, in a second activated state, to convey the auxiliary valve actuation motion, wherein the lost motion adding mechanism is parallel with the lost motion subtracting mechanism in the valve actuation load path at least during the second activated state.

An engine brake rocker arm assembly is operable in an engine drive mode and an engine braking mode and selectively opens first and second exhaust valves. The engine brake rocker arm assembly includes an exhaust rocker arm configured to rotate about a rocker shaft, an engine brake capsule assembly movable between (i) a locked position configured to perform an engine braking operation, and (ii) an unlocked position that does not perform the engine braking operation, and a hydraulically controlled actuator assembly configured to selectively move the engine brake capsule assembly between the first and second positions.

An engine brake rocker arm assembly is operable in an engine drive mode and an engine braking mode and selectively opens first and second exhaust valves. The engine brake rocker arm assembly includes an exhaust rocker arm configured to rotate about a rocker shaft, an engine brake capsule assembly movable between (i) a locked position configured to perform an engine braking operation, and (ii) an unlocked position that does not perform the engine braking operation, and a hydraulically controlled actuator assembly configured to selectively move the engine brake capsule assembly between the first and second positions.

A variable valve timing assembly is provided for extending a duration of an intake valve opening. The variable valve timing assembly includes an intake rocker mounted on a pedestal and operable by a cam lobe to open and close the intake valve. The intake rocker includes a lever extension, and a holding member in the pedestal is lockable in position by a hydraulic circuit in the pedestal to contact the lever extension of the intake rocker and hold the intake valve in the open position. A reset pin in the pedestal is actuatable by the cam lobe to release the holding member to allow the intake valve to close.

An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine decompression mode, the exhaust valve rocker arm assembly selectively opening first and second exhaust valves and including a rocker shaft, exhaust valve rocker arm assembly and a ball engine decompression mechanism. The exhaust valve rocker arm assembly has an exhaust rocker arm that receives the rocker shaft and is configured to rotate around the rocker shaft. The ball engine decompression mechanism is configured on the exhaust rocker arm and selectively actuates a valve plunger causing an exhaust valve to perform engine decompression. The ball engine decompression mechanism includes a capsule assembly having a capsule, a biasing member and a ball. The capsule has a cylindrical body that extends between a first end having an actuation face and a second end having a spring return face.

An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine decompression mode, the exhaust valve rocker arm assembly selectively opening first and second exhaust valves and including a rocker shaft, exhaust valve rocker arm assembly and a ball engine decompression mechanism. The exhaust valve rocker arm assembly has an exhaust rocker arm that receives the rocker shaft and is configured to rotate around the rocker shaft. The ball engine decompression mechanism is configured on the exhaust rocker arm and selectively actuates a valve plunger causing an exhaust valve to perform engine decompression. The ball engine decompression mechanism includes a capsule assembly having a capsule, a biasing member and a ball. The capsule has a cylindrical body that extends between a first end having an actuation face and a second end having a spring return face.